Hi. I am 18 years old, and have been sexually active for a year and a half. I was on the depo shot for 7-8 months; my last shot was due in mid November of last year. I did not have sex at all after the shots had ran out. I had not gotten a real period since I stopped receiving the shots, although about two months ago, I had very light spotting for maybe 3-4 days. Then, on March 23rd I had unprotected sex. We had sex for about 20 minutes, and then an hour later continued for about 30 minutes. He pulled out, as far as I know. The very next day I had some light to medium bleeding. Then for the following three days I had what seemed like a normal period, just slightly lighter from what mine used to be. It has been so long and so I just don't really remember if this seems lighter or shorter than my periods before the shot. I have heard of implantation bleeding, but this seemed a little heavy compared to what people say implantation bleeding is like. So, what is the likelihood that I am pregnant?!?! It is very urgent!!